As a result of their clonal origin, lymphoid tumors present as tumor-specific antigens unique cell surface epitopes related their recognition structures. We have produced lymphoma-specific monoclonal antibodies and demonstrated that the target structure, a disulfide-bonded heterodimer, is the T-cell antigen-specific receptor. Nearest-neighbor analysis of the receptor using chemical crosslinkers demonstrated that the receptor is part of a multichain complex. Recently, we have identified another heterodimer on the surface of T-lymphoma cells. This molecule is serologically distinct from the alpha/beta antigen receptor and may represent a new family of T-cell-specific cell surface molecule. Our current goals are to: (1) use conventional methods and recombinant DNA technology to produce additional antibodies to the components of the T-cell receptor complex; (2) evaluate their efficacy in specific immunotherapy; and (3) further characterize the novel T-cell heterodimer and determine its relationship to the T-cell antigen receptor. (AG)